Aluminum alloy and method of making same



UNITED STATES PATENT OFFICE.

ALUMINUM ALLOY AND METHOD- OF MAKING SAME.

No Drawing.

To all whom it may concern:

Be it known that I, ALBERTO DE LAVAN- DEYRA, a citizen of the United States, residing in Springfield, county of Hampden, and State of Massachusetts, have invented certain new and useful Improvements in Aluminum Alloys and Methods of Making Same, of which thefollowing is a full, clear, and exact description.

This invention relates to aluminum alloys, and the method of making and treating the same. The alloys which I will describe herein are particularly well suited for rolling, forging, extruding, swaging, etc.

The alloys which I prefer to employ-contain small amounts of manganese, magnesium, copper and chromium, with the balance of aluminum and its impurities. I have found that the copper content should be from 2% to 5% with a magnesium content of less than 1% and a combined manganese and chromium content of 1% or less. Whenever I increase the chromium content, I reduce the manganese content proportionately, for I have found "that an inverse relation, in percentages, of these elements is proper for producing the best results. The manganese content maybe reduced to a trace.

The mode of manufacture which I have found to be most suitable is to first prepare rich alloys of aluminum One of these alloys is preferably a 25% manganese one, another preferably a 10% chromium alloy, and a third a 20% magnesium alloy; then a large quantity of aluminum with the proper amount of copper is fused and the proper amounts of the rich alloys added in order to bring the resulting fused mass to the proper composition. For example, a 96% aluminum, 0.5%manganese, 0.5% magnesium, 2.5% copper, 0.5% chromium alloy may be made by adding 2.0 parts of manganese alloy, 2.5 parts magnesium alloy, and 5 parts of chromium alloy to a fused mass containing 88 parts of aluminum and 2.5 parts of copper; or a 94.80% aluminum, 4.00% copper, .7 chromium, .5% magnesium alloy may be made by adding 7 parts of chromium alloy, 2.5 parts of magnesium allo to a fused mass containing 86.5 parts of aluminum and 4 parts of copper. This is the preferable procedure, but I may prepare rich alloys of aluminum with more than one of the alloying materials.

Specification of Letters Patent.

" constituent Patented Jan. 11, 1921.

Application filed August '7, 1919. Serial No. 315,836.

Someoxids Will be present in the fused mass, and I have found that these may be removed in a slag by the addition of a small amount'of arsenic or a compound of arsenic,

which clears up the fused metal so that it may be cast into suitable slabs or billets of even composition, the preferable compound being As O These slabs or billets may then be subjected to a working operation, as forging, rolling, drawing or extruding, before heat treatment. I have found that it is advantageous to so Work the metal before heat treating it. Mere heating the alloy, as has been suggested, does not bring out all the desirable properties, such as high tensile strength and great elongation, which may be obtained by continuing the heat treatment until the alloy has come to a state of internal equilibrium. The time required for this heat treatment varies with the thickness and mass of the article being treated. The preferable range of temperature is 480 C. to 560 C. After the alloy is in internal equilibrium, it is quenched in a suitable bath. 1

The material, after quenching, may be re-worked in any fashion. If. only a small amount of work is done on it, it. may be finished without re-treatment, but if it has been re-worked many times, as in rolling 'thin sheets or drawing small wire, a re-heat treatment is desirable between some of the intermediate Working operations.

I claim:

1. An alloy susceptible of heat treatment, composed of aluminum as the principal constituent and comprising substantial amounts of manganese, magnesium, copper and chr0- mium.

2. An alloy susceptible of heat treatment, composed of aluminum as the principal constituent and comprising substantial amounts of manganese, magnesium, copper and chromium, the copper content being more than 2%.

3. An alloy susceptible of heat treatment, composed of aluminum as the principal and comprising substantial amounts of manganese, magnesium, copper and chromium,-thecopper content being less than 5%. f 4. An alloy susceptible of heattreatment, composed of aluminum as a principal constituent and comprising substantial amounts of manganese, magnesium, copper and-chromium, the copper content being between 2% and 5%.

5. An alloy susceptible of heat treatment, composed of aluminum as a principal constituent and comprising substantial amounts of manganese, magnesium, copper and chromium, the chromium being less than 1%.

6. An alloysusceptible of heat treatment, composed of aluminum as a principal constituent and comprising substantial amounts of manganese, magnesium, copper and chr0- mium, the manganese being less than 1%.

7. An alloy susceptible of heat treatment, composed of aluminum as a principal constituent and comprising substantial amounts of manganese, magnesium, copper and chromium, the combined percentage of chromium and manganese being 1%, or less.

8. A series of aluminum alloys containing a substantial amount of magnesium but less than 1% thereof, 2% to 5% copper, and approximately 1% chromium and manganese taken together, an increase in the chromium content being accompanied by a decrease in the manganese content.

9. An alloy susceptible of heat treatment, composed of aluminum as a principal constituent, containing substantial amounts of both magnesium and copper and further containing substantial amounts, but less than 1% each, of chromium and manganese.

10. An aluminum alloy having an excess of 90% of aluminum, and containing manganese, magnesium, copper and chromium in substantial amounts.

11. The method of making an aluminum, magnesium, manganese, copper and chromium alloy, which comprises making rich alloys of aluminum with each of three of the other components, and adding selected amounts of each of these rich alloys to a fused mass of aluminum with the other component.

12. The method of making an aluminum, magnesium, manganese, copper and chromium alloy, which comprises making rich alloys of aluminum with each of three of the other components, and adding selected amounts of each of these rich alloys to a fused mass of aluminum with the other component, said other component being copper. 13. The method-of making an'aluminum, magnesium, manganese, copper and chromium alloy, which comprises making rich alloys of aluminum with each of three of the other components, and adding selected amounts of each of these rich alloys to a fused mass of aluminum with the other component, fusing the mass and adding a metal to slag the fused mass.

14. The method of making an aluminum, magnesium, manganese, copper and chromium alloy, which comprises making rich alloys of aluminum with each of three of the other components, and adding selected amounts of each of these rich alloys to a fused mass of aluminum with the other component, fusing the mass and adding arsenic to slag the fused mass.

15. The method of making an aluminum, magnesium, manganese, copper and chromium alloy, which comprises making rich alloys of aluminum with each of three of amounts of each of these rich alloys to a fused mass of aluminum with the other component, fusing the mass and adding an arsenious compound to slag the fused mass.

16. The method of making an aluminum, magnesium, manganese, copper and chromium alloy, which comprises making rich alloys of aluminum with each of three of the other components, and adding selected amounts of each of these rich alloys to a fused mass of aluminum with the other com onent, fusing the mass and adding As 6 to slag the fused mass.

17. In the manufacture of aluminum alloys, the step of slagging the fused alloy, which comprises the addition of arsenic.

18. In the manufacture of aluminum alloys, the step of slagging the fused alloy, which comprises the addition of an arsenious compound.

19. In the manufacture of aluminum alloys, the step of slagging the fused alloy, which com rises the addition of AS203.

AL ERTO DE LAVANDEYRA.

the other components, and adding selected 

